9.B.54 The Archaeal/Bacterial 4 TMS Putative DMT (AB-4DMT) Family The AB-4DMT family includes many small proteins, all of which have 4 TMSs per polypeptide chain. Homology with SMR-like proteins has been considered but not established. Additional bacterial homologues may be found in the B-4DMT Family (TC# 9.B.148). This 4 TMS domain may also be found at the N-terminus of a putative archaeal chloride channel, CLC (TC# 2.A.49.6.4). While homology with the DMT superfamily is not established, it appears that families 9.B.54, 9.B.106, and 9.B.148, all containing 4 TMS members, may be homologous.
This family belongs to the N-terminal 4-TMS DMT-like Protein (N4D) Superfamily.
Examples:
TC#	Name	Organismal Type	Example
9.B.54.1.1	Archaeal 4 TMS protein of 171 aas		4DMT protein of Natrialba magadii (Natronobacterium magadii)

9.B.54.1.2	SPW repeat protein of 157 aas and 4 TMSs.		UP of Natrialba taiwanensis

9.B.54.1.3	Uncharacterized protein of 184 aas and 4 TMSs.		UP of Saccharomonospora marina

9.B.54.1.4	SPW repeat protein of 110 aas and 3 or 4 TMSs		SPW repeat protein of Natronococcus jeotgali

9.B.54.1.5	Uncharacterized protein of 121 aas and 4 TMSs		UP of Nitrolancea hollandica